This invention relates to a method for filling gas into a metal container such as an oleo-pneumatic shock absorber or a gas spring.
One prior art method for filling high pressure gas into a metal container consists of forming a small hole in an end wall of the container, filling gas into the container through the small hole, closing the hole by inserting therein a plug and welding the plug to the container. In such case, difficulties are encountered in that it is necessary to remove burrs or the like from the inner edge of the small hole, thereby decreasing the working efficiency, that it is necessary to fabricate the plug separately from the container, thereby increasing the cost for the machining operation, and that it is necessary to control the material of the plug carefully since the plug is formed separately from the container.